US2611474A - Rake classifier and lubricating system therefor - Google Patents

Description

Sept. 23, 1952 c. H. SCOTT 2,611,474

RAKE CLASSIFIER AND LUBRICATING SYSTEM THEREFOR Filed July 7, 1951 I v 7 Sheets-Sheet 1 Q N I N T Q (0 g IO N O Q N u o I 2 o I N I o nb 2 I I (9 I m N INVENTOR: 0

CHAR s HAROLD Sco'rT,

A ORNEY c. H. SCOTT Sept. 23, 1952 2,611,474

RAKE CLASSIFIER AND LUBRICATING SYSTEM THEREFOR Filed July 7. 1951 I 7 Sheefs-Sheet 2 f INVENTORE HAhoLo'sco'lfT.

Sept. 23, 1952 SCOTT 2,611,474

RAKE CLASSIFIER AND LUBRICATING SYSTEM THEREFOR I Filed July '7, 1951 '7 Sheets-Sheet 3 INVENTORZ CHARLES HAROLD ScoTT,

FlG.5-. BY

ATTO EY Sept. 23, 1952 c. H. SCOTT I RAKE CLASSIFIER AND LUBRICATING SYSTEM THEREFOR Filed July 7, 1951 7 Sheets-Sheet 4 l I Q II" 665 s I lll -'I 'QJWIIIIIIIM as IO M l 52 Nv NTo I CHARL E S HAOLD SCOTT,

C. H. SCOTT Sept. 23, 1952 RAKE CLASSIFIER AND LUBRICATING SYSTEM THEREFOR 7 Sheets-Sheet 6 Filed July 7, 1951 INVENTOR:

C. H. SCOTT Sept. 23, 1952 RAKE CLASSIFIER AND LUBRICATING SYSTEM THEREFOR 7 Sheeis-Sheet. 7

Filed July '7 IIIIIIIIIIII i atent'eci Sept. 23, 1952 UNITED sTATss P TENT o FFICE --ration of Delaware Application July 2,1951, s nsin 235 633 (or. ros -224) 5 Claims.

This invention relates to what the wet classification treatment of solids as' in metallurgical, ore dressing, or other slurries is known as the reciprocating type of rake classifier which is capable of fractionatingthe mixture'of solids contained in a slurry into a coarse solids fraction and a fraction'offines. More particularly, this invention relates to such a rake classifier and lubricating system therefor;

. It is amongthe objects to providesuc'h a rake classiilerwith a lubricating systemthat is simple, compact; efficient, reliable; as well as accessible, for continuously"supplying'lubricating oil to the sliding" bearing faces" in the a rake actuating mechanism of a .classifiersuchas disclosed and exemplified in the coependin'g patent application of'Charlejs H. Scott, Serial No; 8833-19; such .a lubricating system to supply; lubricating oil by continuous pump sustained" circulation to the reciprocally sliding bearing portions" peculiar tothe rake" actuating mechanism of that machine.

A' clearer outline'pf this rake actuating mecha-' nism aslwell as of the lubricating problem arisingin. conjunction therewith will appear furtherbelow.

"Generally speaking a classifier of the recipro eating rake typeYbriefly termed "a rakeclassifier has a continuous supply of solids carrying slurryfed to a loath ofr'pool contained in the-classifier, and a rake mechanism operates in theclassifier to fractionate' the slurry" solids ,fed to the'bath according to size into a fraction of coarsesolidsalso called thesands anda fractionof'lighter or smaller .solidscalle'd theflnes; both fractions to be delivered continuously and separately" from such a machine; v

Such a rake'classifier"comprises a'tank having an inclined" bottom or deck; the lower end of which makesthe' deep end of the slurry pool ing into the'deep'end of the'pool.

the tank bottom'whereby settled solids are conveyed up along the'deck towards emergence and discharge, and a longitudinal return stroke du -r ingwhich the rakeis' kept raiseda suitable dis-- tance from the'bottom'. That is to saygthe-rake structure is lowermost and is in solids-raking relationship to the deck during the upward rak-- ing strokes, and is uppermost as well as a dis laterally in cpposite directions from the sha 2 tance away from the deckduring the downward return strokes, and it is t'o' he raised and lOWered relative to the inclinedtank bottom during the transition between raking strokes and return strokes. In this way, the coarse solids fraction or sands are delivered by therake structure from the shallow endof the-pool to c'onstitute thelsw called rake productwhile the-fraction of fines being of a small enough size to be keptin'suspension by the rake agitation'in' the pe'olis delivered by way of liquid that isallowed :to overflow from the tank at the deep 7 end i of the'=pool..

More particularly, the rake classifier disclosed in the above-mentioned Scottapplication =isof the twin-rake-type in which two rake structures ope-rate side by side in the tank, operat-ively-isupk ported by and from their actuating mechanism in such a manner that the weight of the one rake structure balances that 'of the other as I the rake structures are raisedgandllowerred in ralterlnation withrespeot to the tank bottom. lniother words, themechanism operates insuch a manner thatanupwar-di solids raking stroke =irrrpa'nted to the one rakestructure coincides with .aldownrward" return stroke of the other rake Structure; while the loweringof one rake structureaitthe end :of its'return stroke cOinQidQS w th he-ra sins of theother rake structure an the-endof i s solids rakingwstroke.

The: rake actuatin mechanism the-ewes: mentioned Scott applic ti n c mp s s a itsbasic element an inclined oscillatable shaitwhichextends parallel to and is coextensive with longitudinal extent of'the rake-structures as w l as parallel to the inclined tank bottom or and it extends medially of anddi-re'ctly above the deck. This longitudinal shaft has at its up 'p'er end a pair pf upper arm structure's extendi and similarly it has at its lower end a pair of lowerv arm structures extending laterally in op?- posite directions from the shaft, all 3 5 1 Structures'being rigid with the shaft-land'oscillatahlei or rockable therewith; The upperarm structlrr furnishoperating support for the upper "end por tions of therespective rakestructures'; while the lower arm structures inrnishoperating support for the'lower end portions of the respective r-ake structures, each rake structure" having -an u p wardly extending upper and lower rake-"hang r" or bracket rising rigidly'from the rake structure: whereby the rake-structures are suspended-from the'arm structures. Toprovide for longitudinal: reciprocating movement of the rake structures each structure is provided at each. treeend thereof with a longitudinal track memkier'having';

a fiat track face extending parallel to the medial shaft, upon which track member is slidably supported a, glide shoe provided at the upper end of a, respective hanger or bracket of a respective rake structure. The track member is pivotally mounted upon the arm structure so as to be capable of slight compensatory oscillating movement about a longitudinal axis which is parallel to that of the oscillatable medially disposed shaft. In this way, one rake structure is supported operatively by and from a pair of track members, an upper and a lower one, at one side of the inclined longitudinal shaft, while the other rake structure is similarly supported by and from an upper and a lower track member at the opposite side of that shaft.

A drive mechanism is provided whereby the oscillatory movement of the longitudinal shaft is coordinated to the longitudinal movements of the rake structures in such a way that, after the crossarm constructions have been tilted in one direction by the actuation of the oscillatable shaft for lowering one rake structure and raising the other, an upward solids raking stroke is imparted. to the lowered structure while simultaneously a downward longitudinal return stroke is imparted to the raised structure. At the simultaneous completion of both strokes the crossarm structures are tilted in the opposite direction by the actuation of the oscillatable longitudinal shaft, whereupon reversed strokes are imparted simultaneously to the respective rake structures, whereupon at the completion of the strokes the cross-arm constructions are again tilted in the opposite direction for completing the bodily cyclic movement or cyclic path of the rake structures.

A problem lay in how to properly lubricate and maintain the track members in view of the fact that these classifiers must operate for instance inore dressing plants where it is virtually impossible to fully protect and seal off the sliding bearing faces of the track member against the deposition thereon of abrasive-laden dust. Hence the problem of providing a lubricating system in and for such a classifier.

.In order to protect the sliding bearing faces of the mechanism as far as possible against the undesirable effects of dust and against excessive wear and tear, there is included in the lubricating system of this invention a track construction which provides a trough-shaped doubletrack member in which a pair of unitary troughshaped tracks extend parallel to one another with an elongated narrow opening provided between them. More specifically, in this doubletrack member the ends of the two trough-shaped tracks are interconnected at their respective ends by a short transverse trough portion at each end so that the double-track member in effect constitutes an endless trough of which the parallel long portions contain the tracks proper. A suspension bracket or hanger rising rigidly from a respective rake structure extends upwardly through the elongated opening between the tracks of such a member and terminates in a T-shaped end provided with a glide shoe at each end of the cross beam of the T-shape, each such glide shoe engaging and being supported by a respective track in the double-track member. In this way each end portion or each hanger of each rake structure is supported from a double track member with the rake hanger depending from beween the two tracks of the double-track member, and the two glide shoes extending into the respective longitudinal trough portions which constitute the tracks in that member. A removable cover closes the entire endless trough of such a double-track member, making it in effect a double track casing within which a pair of glide shoes operate relatively well-protected.

Each double-track member is oscillatably carried by and between a pair of supporting arms which constitute one side or one-half of the aforementioned cross-arm construction of the medially extending inclined oscillatable shaft. That is to say, the double-track member is disposed between and carried by the free ends of the pair of supporting arms and is oscillatable thereon about a longitudinal axis by means of a pair of pivots, one pivot extending from each end of the double-track member, each pivot having its bearing in the free end of a respective supporting arm.

The rake actuating mechanism of this classifier construction comprises a drive head mounted at the high end of the classifier deck, for imparting oscillation to the medial shaft and also for imparting reciprocating movement to the rake structures so timed with respect to the oscillations of the shaft that each rake performs its cyclic movement although with a phase shifting of between the movements of the two rake structures. The drive head comprises a gear box or housing fixed with respect to the high end of the classifier tank, in which is rotatably mounted a driven transversely extending rake reciprocating crank shaft having a crank at each free end thereof with a connecting rod betwen each crank and its associated rake structure. In this way, since the cranks are offset 180 with respect to each other the rotation of the transverse shaft will impart to the; rake structures longitudinally reciprocating movements with a 180 shifting of phase. In order to furnish the up and down transverse component of the cyclic movement of the rake structures, a cylindrical cam member is provided coaxial with and fixed upon the intermediate portion of the transverse crank shaft for effecting the properly timed oscillation of the longitudinal inclined shaft. Therefore, rotation of the crank shaft will impart to one of the rake structures its elevated return stroke, while imparting to the other rake structure its solidsraking stroke. The alternate raising and lowering of the rake structures during the transition between the raking stroke and return stroke is effected by the cam member positively engaging an arm rigidly extending from the upper end A portion of the longitudinal inclined shaft so as to oscillate the shaft in a positivemanner and in properly timed relationship with'respect to the longitudinally reciprocating movements or strokes of the rake structures carried by the cross-arm constructions of that shaft. Thus during an operating cycle of the actuating mechanism the rake structures are motivated longitudinally in respective opposite directions by the cranks after the longitudinal inclined shaft has been rocked by the cam member in the one direction and has thus brought the rake structures to their respective raised and lowered positions. Substantially at the end of these longitudinal movements or strokes of the rake structures the longitudinal inclined shaft is rocked in the opposite direction bythe revolving cam member thus lowering the one rake structure at the end of its downward return stroke while raising the other rake structure at the end of its upward solids raking stroke, with respect to the classifier deck.

While, this. rakeaactuating. mechanism or the; co-pending Scott. application .constitutes a recent;

and successful developmentv in. classifiersconstruction, and particularly in. rake actuating mechanisms, it presented the problem aboverindicated regarding the lubrication. of; the longitur dinal tracks, in view of the factthatto seal off the trackscompletely against-the. dust and abra-v sive laden atmosphere of. their. operating; Fin,-

vironment appears to be i-n; 1practicable,evemwith the novel and otherwise. efiicient constructionof. the track members or track casings provided in and by this classifier.

This invention is based upon-the concept that. rather than providing lubrication with grease-oi the conventional high consistency as with conventional grease-cup fittingsthere shouldbeemcontinuous circulation of lubricating. oil from an oil reservoir to the tracks and from the tracks to the oil reservoir, byway of .a circulating oil pump, the oil thus to serve for carrying andsifier tank,'is'to bepumped back tojthe'high point I at the head end of the classifier.

It is among the objectsof this invention to provide for the operating tracks ofthe rake structures a simple and compact as' well as efficient oil circulating lubricating system, such a system to be readily accessible andserviceable, in its essential parts especially "with respect to a pump and an oil reservoir provided in the sys-' tem, the pump moreover tohave' simple and compact mechanical driveme'ansto be actuated directly by the operation of the rake actuating mechanism.

In view of the environmental structure as presented by the classifier and its appurtenances, the organization of the 'lubricatingjsystem is to be such as to readily lend itselfjforwhatever manipulation is necessaryto-efiecta change of oil'in the reservoir, or to inspectand ascertain the condition of the oil in the reservoir. f

Another object is to provide such 'a'lubric'ating system with a pump having a'minimum .o'f'moving actuating parts and with the parts welliprotected by and enclosed within the system itself, yet readily accessible, inspectable and removable, which system furthermore 'is to be .capableoi being readily installed'upon the classifier.

These objects are attained by providing a lubri-' catingsystem that extendssubstantially along,

and closely hugs the length of the medial. inclined oscillating shaft, a plunger .oil. pump .as well' as an oil reservoir beingqprovided in close association with each other and characteristically disposed at the upper end ofthat shaft, with. the pump plunger to be reciprocated byand vattl e same frequency as that of the oscillations of'the shaft.

According to one feature, the -pump plunger is reciprocated directly by the-oscillations of themedial inclined shaft, namely by an arm or: finger extending from the upper end; portion of; the

medial. shaft. into mat. engagement: with-the pump plunger'so that. the oscillation: ofztheishai't'z will. impart corresponding. reciprocating; move-r. mentsto'the pump plunger... I

According to a; further and. more speciflc tea.

ture,.the. pump is structurally and functionally-1 directly associatedwith andImounted upon'and'; carriedby an oilreservoirto constitutea compact unit therewith, the reservoir: in turnbeing carried. by andmounted upon the drivehead or gear'casing atthe high or head end of theclassifier deck; According. topthis'feature thereis established a. unique, compact, and efficient relationship of parts, in thatthe free end. or stem. of: the pump.

plungerv protruding from the pump: cylinder as well. as the shaft-oscillated actuating. finger:

engaging the stem operate inside the reservoir.

and are submerged in the body of oil therein; Further particularized, this: pump carried by the ,oil reservoir at the head of the classifientank has a double-acting plunger comprising apistom portion at its outer end and a stem portioniatits inner end. At its outer side the .piston portion draws spent oil drained from the tracks from alow collecting point at the lower end of the medial;

shaft, and delivers such spent oil into the resere' voir at the top, namely into a space or chamber.

at the receiving side of. a screen provided inthe.

reservoir. In this way the action of. the pump causes oil to be passed through the screen or filter member and to rise from the dischargeside. of the screen into a space or chamber-providedwby the reservoir at that side of the screen. The

inner side of the piston, which is annular extend- I ing around thestem, draws filtered oil fromabove the screen and delivers it for discharge. and. dis:- tribution to the upper tracks of the rake-structureswhence the oil may gravitate throughzsuitt able pipes to the lower. tracks and from there: rto"v a collecting point whence the pump again draws the spent oil to thereservoir. at. the topend of the shaft. That is to say, an axial extension of. the upper end of the medial shaft: being .of reduced diameter extends sealingly througlrthe-v wall of theoil reservoir, the pump-actuating fin.-. ger elementbeing fixed to that extension within the confines of the reservoir. Coactionbetween the actuating finger and the pump plunger is established by the pump being mounted upon the reservoir itself in such a manner thatthestem portion of the plunger extends inwardly intothe reservoirand into direct engagementrwitli. the.

oscillatable actuating finger within the body of.

oil held by thereservoir. More specific features lie in the particular structural and functional relationshipsbetween" the pump and the-reservoir in conjunctionwith the structuraland functional relationships. between the reservoir and the rakeactuating mechanism.

Therefore, a feature liesrin the fact that;the

reservoir in effect surrounds the upper end :p'ol'itionof the medial shaft, and. is carried byand rigidly mounted upon the gear casing of theaforementioned. drive head,'that further the pump cylinder has afrontxo-r outer open-ended flangedend portion and an inner'endportion closed bythe free rearend or stem of: thepump plunger; The. inner .end portion .of the cylinderwith :the

outeri'fianged end'of the pump cylinder and'is readilyremovab'le for inspecting the pump interior as well as for inspecting the ports and valves.

The pump plunger is double-acting in that the outer side of the plunger piston handles a relatively'l'arge cylindrical volume of fluid, while the otherside of the piston, which is smaller and annular surrounding the plunger stem, handles a smaller annular volume, namely the volume surrounding the plunger stem. That is to say, as the plunger is moved inwardly into the reservoir by the actuating finger the outer side of the piston draws a relatively larger volume ofspent oil from the lower oil collection point into the cylinder, while delivering a smaller oil volume notably filtered from the other side of the piston into a discharge compartment associated with the reservoir and disposed above the pump so that oil overflowing from this discharge compartment may gravitate to the tracks. As the plunger is moved into the opposite and outward direction with respect to the reservoir, it delivers the aforementioned larger volume of oil inclusive of impurities or grit or the like to a space or chamber in the reservoir beneath the screen, while a smaller volume of oil is simultaneously drawn from above the screen for delivery to the discharge chamber and thence to the tracks.

With such organization of the lubricating systemand such disposition of the parts, the condition and amount of oil in the reservoir is readily asc'ertainable, an oil change can be readily effected, and the operation of the pump can be readily observed.

In summary, this invention comprises an oil circulating lubricating system for a twin-rake classifier in which the bodily cyclic motion of the rake structures is effected by a rake-actuating mechanism which comprises an inclined medially disposed oscillatable shaft having a pair of upper arm structures extending laterally in opposite directions from the shaft as well as a pair of lower arm structures extending laterally in opposite directions from the shaft. Each rake structure is suspended from a pair of arm structures, an upper and a lower one, upon which the rake structure is longitudinally reciprocatable by means of track members which in turn are also oscillatable upon the arm structures about an axis coextensive with that of the o'scillatable shaft. A drive head at the upper end of the classifier deck imparts oscillations to the shaft as well as longitudinally reciprocating movement to the rake structures. The oscillations of the shaft and the reciprocations of the rake structures together in coordination impart to each rake structure the required cyclic movement which comprises an upward solids raking stroke, an elevated return stroke, and alternate raising and lowering of the rake structure as transitional parts of the cycle between the raking stroke and the return stroke.

The lubricating system comprises a pump and reservoir unit disposed at the upper end of the deck with the upper end extension of the oscillating shaft reaching into the reservoir for reciprocating the pump plunger disposed within the body of oil in the reservoir. The pump is doubleacting to draw filtered oil from above a screen in the reservoir for delivering it to thetrack members whence it gravitates to a low collecting point. the pump also to draw spent oil from the low collecting point for delivering it to beneath the screen in the reservoir.

The pump cylinder has its'free inner plunger 81 end portion extending into the reservoir, while an outwardly exposed as well as" detachable end member represents a valve head closing the opposite or outer end of the pump cylinder.

As this invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within the metes and bounds of the claims, or of forms that are their functional as well as conjointly co-operative equivalents, are therefore intended to be embraced by those claims.

In the drawings, Figure 1 is a somewhat diagrammatic plan view of the rake classifier with rake-actuating mechanism and having the lubricating system therefor merely indicated by the oil reservoir at the head end of the tank.

Figure 2 is a longitudinal section of the classifier along the line 2-8 of Figure 1, comprising a side view of the oil reservoir.

Figure 3 is an enlarged plan view of the parts of the rake-actuating mechanism and of the lubricating system associated therewith.

Figure 4 is a side view of the parts and lubricating system of Figure 3.

Figure 5 is a head end view of the rake-actuating mechanism taken on line 5-9-5 of Figure 4, with an end view of the oil reservoir and oil conduits leading therefrom and thereto.

Figure 6 is an end view taken on line 66 of Figure 4, showing the foot end of the rake-actuating mechanism and end view of the spent oil collecting point and oil conduits leading thereto and therefrom.

Figure '7 is a part-sectional view taken on line I-'l of Figure 6, showing the spent oil collecting Point from the side.

Figure 8 is an enlarged part-sectional detail side view of the oil reservoir taken on line 8-8 of Figure 5.

Figure 9 is a top view of the oil reservoir of Figure 8, with its cover removed.

I IZ-IZ of Figure 10.

Figure 13 is an enlarged horizontal detail section of the pump, taken on line Iii-l3 of Fig ure 10.

Figure 14 is a detail perspective view of the oil circulating pump and of its immediate structural environment, with the valve head lifted off in a manner to illustrate the operation of the Figure 15 is an enlarged longitudinal sectional view of one of the track members with cross head and operating tracks protectively encased therein, and oilsupply and discharge connections therefore taken on line |5l5 of Fig. 4.

Figure 16 is a vertical sectional view of-the track member taken on line Iii-l6 of Figure-15. Figure 17 is a top view of the track member, taken on line Il--l1 of Figure 15, with the cover plate of the track member and the cross head omitted.

The lubricating system of this invention is as-- of the deck.

sociated. with the rake-actuating mechanism of aatwin-rakeclassifier which in Figures land 2' comprises a tank It! having an inclined bottom orrdeck. I l,.an.end wall. l2 rising. from the lower end of the deck and provided with an overflow weir I3,- .a pair of sidewalls l4 and i5, and an intermediate partitioning wallilfi parallel to the sidewalls and defining a two-compartment tank in which.operate respective'rake members I! and I8. extendingparallel: to one another. as well as parallel to the inclined tank bottom. The lower end-portion of each. rake member operates in a pool .of' solids-carrying slurry indicated by an overflowlevel L defined by-the elevation of weir 13, the pool in each tankcompartment having a continuous supply of slurry fed thereto indicated by arrow A. i

Both rake members-I1 and iii are actuated by a single drive mechanism, each rake member to perform. a bodily cyclic motion whereby it main tains its slurry'pool sufiiciently agitated to cause the finer solids or so-called fines among the slurry solids to remain in suspension and to be discharged from the pool byway of overflow weir l3, whereas the heavier solids sink to the bottom where they are'moved up stepwise. by the rake members-along the deck to emergence from the pool and finally to discharge frorn'the top end Each rake member has an upper and a lower hanger or bracket rising rigidly therefrom, by means of which hangers the rake member is operatively suspended from a. rake-actuating mechanism which imparts to each rake member the'cyclic bodily movement which comprises an upward solids conveying stroke along the deck, an elevated return stroke with rake member spaced away from the deck, and-transverse up and down movements between the conveying "stroke and the return stroke.

The rake actuating mechanism for imparting such cyclic movements to the rake members comprises an inclined oscillatable shaft 19 coextensive with the inclined deck and disposed centrally of the tank, namely directly above the partitioning wall Hi; This shaft has'its lower end supported ina bearing 20- and its upper end in a bearing which is provided by a drive head 2| and indicated at 20 in Figure 8. The drive head 2! may herein be termed a compound F drive head because itimparts oscillatory motion to the shaft I9 as well as reciprocating motion to the rake members, both motions be-v ing coordinated in a -manner toproduce as a 'compo'und'e-ffect the desired cyclic-movement of therakemembers whereby the rake members "move in complementary fashion in that the one performs its solids raking stroke as the other performs its return stroke and vice versa, and

theone rake member is raised as the other is lowered and vice versa.' The drive head 2| is supported by and mounted upon the upper or head end of the tank, that is at the upper end of the sloping' deck 1i thereof.

The shaft'I-Q has rigid'therewith an upper pair v of laterally extending arm structures, the one arm structure comprising a pair of arms 22 extending laterally in one direction, and the other arm structure comprisinga pair of arms 23 extendin laterally in the opposite directions, from the shaft; anda lower pair of similar laterally extending: arm structures, namely one arm structurecomprising a pair of arms 24 extending laterally. inione. direction, and another. aa'rm struccomprising-1a. pair: .of arms- 25:- extending 10 laterally in the opposite direction. The upper pair of arms 22 carry the upper end of rake member I! while the lower pair of arms 24 carry the lower end thereof, the rake member ll be: ing suspended from these arms 22 and 24. by way of hangers or brackets 26 and 21 rigidly rising from the rake member li.- The upper hanger 26 isslidably supported upon an upper track member 28, whilefthe lower hanger El is supported upon a, lower track member 29,:which track members in turn. are carried by the arms 22 .and 24 respectively. That-is to say, each trackmember has its. ends supported by a. pair of asso--.- ciated arms, for instance the track member 28 is. supported by and. between the free. ends -.0f its pair of arms 22 and .by means of a pair of end trunnions in-a manner, whereby the track member is rendered capableof slight oscillatory movement about its longitudinal axis which: is coextensive with and parallel to that'ofthe-oscillatory shaft [9. Track member 29 is similarly supported for oscillation by arms 24. Similarly, the rake member I8 is supported through .a pair of hangers or brackets l8 and N an upper track member 28 oscillatably supported by arms 23 and a lower track. member 29 oscillatably supported by arms 2-5. Thetrack members hav'e operating tracks proper protectivelyencased, such members. therefore to be more clearly described further below.

The-mechanism of the drive head 2|. iscon,- tained in a housing35 and isdriven by a transverse shaft T from a prime mover not-shown...:This drive head functions to oscillate the shaft 1 l9 substantially at the completion ofeach longitu; dinal stroke of the rake members, thereby im parting to these members the required, cyclic step-by-step solid movement. In fact, the drive head 2! comprises a crank shaft K driven by the shaft T, the crank shaft K being formed at its free endswith cranks K1 and K2 respectively, which cranks have a 180 offset respective to each other. -=The cranks Ki andKz reciprocate respective connecting rods R1 and R2 which operatively connect-the cranks with respectiverake structures 11 and I8. v i I In order to keep the operating tracks in; track members 28, 29,28 and 29 continuously lubricated with everchanging oil effective tofiushimpurities from the. tracks, there is provided an oil circulating system. which comprises, characrteristically; an-oilreservoir 36 supported by and connected with the drive head 2| (see Figure "2) the reservoir in turn having mounted thereinlan oil circulating: plunger pump P actuated from the oscillatory shaft t9, namely by an axial extension 31 thereof the extreme end of which has fixed thereon a finger'38 for directly engaging and reciprocating the pump plunger, by the oscillation of shaft l9, aswill be explained in detail further below in conjunction with ;.detail drawing Figures 8 to 13. a

However, the lubricating system as awhole will now first be outlined by reference to Figures 3 and 4. The oil reservoir 36 is, mounted upon the extreme outer end of the drive head 21 and carries init. the oil circulating pump indicated at P. This is a double acting pump, the detailed construction. and, arrangement of which will bedescribed further. below. That is, the pump draws into the reservoir 36 spent oil from a low point of. the rake-actuating mechanism, to .which it has gravitated from the track members, while at For carrying the oil to and from the track members in circulation the lubricating system comprises a pair of symmetrically disposed oil discharge and distributing pipes 40 and 4| each of which leads off a respective side of the reservoir 36. The conduits 40 and 4| are stationary pipes disposed each at a respective side of the drive head 2|, the ends of which pipes are connected through flexible tubes 42 and 43 to respective upper ends of the upper tracks 28 and 28*, whereby they are adapted to feed oil to the tracks through their upper trunnions 39 and 39 herein also termed the inlet trunnions. The oil having served as lubricant for the tracks of track members 28 and 28 while flushing impurities therefrom gravitates from these track members through their lower track trunnions 39 and 39 herein also termed outlet trunnions, and intopipe conduits 44 and 45 fixed to the oscillatory shaft l9 and leading to inlet trunnions 39 and 39 respectively of the lower track members 29 and 29. That is to say, the oil from the two upper track members 28 and 28 now enters the two lower track members 29 and 29 by way of inlet trunnions 39 and 39 respectively, then once more to serve as lubricant for the tracks while flushing impurities therefrom when gravitating from these tracks through their outlet trunnions 39 and 39 respectively.

From the outlet trunnions of 39 and 39 of the lower track members 29 and 29 the oil gravitates into respective pipes 44 and 45 con-- verging to a common point of collection in that they terminate in a collecting chamber 46 mounted upon the lower end of the oscillatory shaft An oil suction connection whereby the circulating pump P may draw spent oil from the collecting chamber 46, comprises a suction pipe 41 leading from the collecting chamber 46 upwardly along and fixed to the underside of the oscillatory shaft |9 to a point 48 near the drive head 2|, a stationary tube 49 leading from a point 56 near point 48 along the underside of drive head 2| and then again upwardly to the pump P and thus to reservoir 36, and a flexible tube inter-connecting the end 48 of movable pipe 41 with end 50 of stationary pipe 49.

With such a combination of rigid pipe and flexible tube connections provided between the oil reservoir 36 at the head end and the collecting chamber 46 at the foot end of the classifier tank, the oil circulating pump P operates at one piston side thereof to continuously draw spent oil from the collecting chamber 46 into the pump cylinder and to deliver it into the reservoir 36 at a rate which causes it to rise through a filter medium in reservoir 36. Filtered oil from above the filter medium is drawn by the opposite side of the pump plunger into the pump cylinder and delivered by the pump to the track members.

Referring to Figures 8 to 13, the reservoir 36 consists of a bottom 52, a vertical rear wall 53, a pair of vertical side walls 54 and 55, an irregularly shaped front wall 56, and a cover 51 constituting the top of the reservoir and fastened thereto as by screws 58. A filling cap or breather B is shown to be provided in the cover 51. Horizontally across the lower portion of the reservoir 36 and near the bottom thereof extends a screen or filter member or filter medium 59 dividing the reservoir 36 into a spent-oil receiving lower chamber 60 underneath the filter medium 59,

and a filtered-oil chamber 6| above the filter medium 59. Spent oil is delivered by the pump 12 into the chamber and is forced by the pump to rise in the reservoir and through the filter medium 59 into chamber 6|. In the top portion of reservoir 36 there is provided a trans verse partitioning wall 62 defining a pair of discharge and distributing chambers 63 as defined by a feed splitting sub-partition 62 to which oil is supplied by pump P through an upstanding tube 64 leading from the pump in chamber 6| upwardly and terminating in a spout 63 for delivering oil into chamber 63. In this way, filtered oil from the reservoir may be continuously pumped to chambers 63 incident to the oscillation of the-shaft l9, and the reciprocation of the plunger of pump'P, the oil to, overflow from chambers 63 into distributing pipes 46 and 4| for lubricating the track members.

The construction as well as the function of the double-acting pump P will be more clearly understood by reference to Figures 10, 11, 12, 13. Ihis pump is mounted in the side wall 54 of reservoir 39 and comprises a cylinder 65 having an inner end portion 66 extend into upper chamber 6| of the reservoir, namely by way of an opening 6'! in the wall thereof, and an outer flanged end portion 68 fastened to the outer face of the side wall 54. A plunger or plunger member 69 of the pump comprises a piston or piston portion 69 and a stem or stem portion 69 and is reciprocable within the cylinder with the stem portion extending or projecting from the inner end of the cylinder freely into oil containing chamber 6|. Indeed this projecting end'of the plunger has a notch or lateral recess 10 in which engages the free end of the oscillatory actuating finger 38 already referred to above in conjunction with the description of Figure 2. The piston portion 69 is provided with an annular piston seal 69, While a stationary sealing ring 69 is provided in the cylinder wall for sealing engagement upon the stem portion 69 The plunger member 69 is double-acting in that it has an effective outer full piston face F1 and an effective inner annular piston face F2, each of which piston faces is effective to draw oil into the pump cylinder and to displace it therefrom, by way-of inlet and outlet check valves provided at each respective end of the cylinder, such valve ar rangements to be presently described.

The pump cylinder has a valve head 1| resembling a rectangular plate member of the thickness t and the sides a and b. This plate member has an unbroken outer face H and an inner face 1| contiguous with respect to and matching upon the outer face of the flanged end portion or cylinder flange 68. The valve head 1| consists of transparent material such as a transparent type of plastic, for example Lucite." This valve head 1| registers with the rectangular cylinder flange 68, and it has a hole 12 in each corner registering with similar holes 13 in the cylinder flange, so that both the valve head 1| and the cylinder flange can be fastened one upon the other to the outer face of side wall 54 of the reservoir as by means of screws 14.

The functional relationship of the valve head in conjunction with Figures 11, 12, 13, and particularly also in view of Figure 14.

The valve head 1| has an intake passage 15 (see Figure 12) the lower end of which terminates at the bottom edge of the valve head, which lower end has connected theretothez'spent-oil The valvehead' l I iurthermorelhasa dischar I passage 8%] through whichsthe outer ;,faoe of the plunger piston :may dischar e .1011 iron; the

.oylinder into the. lower chamber 6.0. .of-zthe.rater-- voir. That; is to say, the discharge passage 15.0-

comprises a compound bore, namely :aavertical length .of .bore .liI. in upward continuation of the. vertical length of bore. :l5,-*the1bore.;8.I eon.- tainingra ball. check valve B2,:a; horizontallensth ofibore; 83 :and a vertical length of bore :85 leading downward from the horizontal length and into a transverse and dOWIlWSIdlYLiIlGli-Ilfid terminal length of boreifii (see:.also:Flg.. 10)..having a terminal openingtfi. (see :11) inter ruptingthe inner iace atl of thewalve head II. The terminal opening 8:6 registers::thr0.ugh afhole 86 iniflange .68 with;th.e;adiaoent .endzofa bore -81 (.seeJ-Fig. 11.0). provided in :the adjacent wall portion of reservoir .35, :so that, incident-tothe reciprooationof. the plun er-5.9; the out r pi ton face. F1 displaces. oil from the oylinder through the. dischargewpassageyfifl by way of check valve e2 into the lower "chamber :69 oi. the reservoir,

whence oil must; rise throu h :thefi1ter medium 159 into th pper :chamber .;6 I.

Also incident rtev the reciprocation of the plunger lit. the innerannularplunger.face F2 drawsifilteredoil throu h ball check valve 68 provided '1 in. the cylinder zwall at the. under side thereof .'-fr0m .oha-mber-fil into the annular space .119 surrounding. the plunger s em within th eylinder, to discharge the oil from the cylinder through :aball .che valve 9.0 (and throu h the above-mentionedupstanding tube 64. into the distributin Qhambers 63 Thoconstruotion of the track members isshown inatheaseo io al views of the track-memb r 28. as shown in Figures 15 and 16. The track meme "her. is the .form of a casing .91 and presents the basic .shape 1.01- an .endless groove which of itself .in. planview appears asansexcessivelv elemgated Q-shapedefininga slot-like opening 0 and havinga pair :of parallel long groove portions -92 and 9L3 embodying. and providihgapair of tracks 52 tandxflis zand a pair of short-transverse 'con necting'groove portions-Q4. and-85 at the resins,- tive ends of. the tracks. .The endless groove of this casing member or castin iis :defined by a bottom portion v96, on inner-endless wall portion-9T rising from the inner-edge oitthe bottom portion, and a correspondingly shaped but higher endless wall Strising fromvthe outer edge of the bottom portion. A cover plate 99 conforming 'to theplan view outline of the outer wall is fastened to the top thereof as "by screws I00, the coverplate-thus being spaced a distance: (1" from the top edge of the low wall 91.

The casing BI isformed at each end thereof with a trunnion I0! and 102 respectively, the trunnion IOI being what was above termed the ,oil inlet trunnion, while the trunnion I02 was termed the oil outlet trunnion. These trunnions are coaxial with respect to' each other and 31:4 axially ooextensive'rwith"sandaparallel.itoztheraxis of the oscillatory shaft IS. The trunnion J01 isrrotatableinza eapelike end 'bearingtmember. I 03 having :anaxial bore lflte and also .:having :-.a bronze bushing I103, which ibearingrmember iis :oarried :in and by one of. 'the anus .22.:andiis fastened thereto by -a..1flange Ifliiormed: atthe .end' of rthe bearing member :and. fastened rtotarm 12.2 as by means .of. screws 1 [0.5. Interpose'd :be:- ftween'rthe end "ofitr'unnion IBI audits bearing member I03 isathrust'washer M6; The trimnion I 0.I has 'an'axial hore'fllii through which aexten'dsa length of .tube I08: from-the inner .end .ofbore 103 the other end of bore 103 211011- necting with. the oil supply pipe 42. ThllSjBJl oilzstreammay. enter. by wayzorzendj-bearing mem ber I03 andthroughxtrunnioniill .into one.end;oI

the casing or casing member ill, the oil :stream to. split at this point to supply both of the parallel tracks 92- and 93 The split oil streams have ing "passed down .along the inclined tracks .in their respectivecgroove portions join in thei lower end of the casing member .9I, whence thezoil vdischargesgravitationally through :a abore il 69,- in the outlet" trunnion I02 and through .a :tube'-' I I0 extending coaxially from bore I09tinto a hollow of collecting space I II provided in the outer end portion of acapdike endhearing.memberrlill having a-flo-ronze bushing I I 3 carrying 'theptrunnion I02, with a thrust washer I I4 interposed betweenthecend of the trunnion and its-bearing member. The oil discharge pipe 44 is connected to the shearing member II2 so that the. oil-may gravitate .therethrovgh fromthe collecting Space Slidable upon the double :tracks ;.92 -and 39.3- is a cross. head ll lehavinga pair of downward;- ly Jfacing slide shoe elements H5 and 61131;

:the .bottom whereby the cross; head .is supported upon "the tracks, and; also having a :pair of :up- .wardly facing slide .shoe :elements I11 and '8 to engage the underside of. cover plate -99. In fact, the cross head 'il l comprises a {F- shaped swingableimember .I I 5 (see .Fig. 1-6) with cross-beam portion of theT-shape constituting 'a pairof trunnions M9. and #26 carried .by-bear- 'ing members HI and I322. respectively, .:eaoh bearingmember in turn consisting'ofa pair'of half shells, each half shell rep-resenting onexo'f the afore-mentioned upper and lower :slide zs'hQe elements. Thus the bearing member I,21I comprisesa lower'half shell l m and an upper half shell I 21 provided with the aforementioned lower and upper slide shoe elements H5 and Hltrespectively, while the bearing member .122 .com-

prises alower half shell tZZ and an upper half 7 shell I122 provided with the aforementioned lower :and upper slide shoe elements H6 and H8 respectively. The half shells of eaoh'bearing 'memher I2! and I22 are bolted together as indicated b-y screws Iii-land I24 in Figure 15.

The T-shaped swingable member H5 ofythe cross head has a central vertical dependingstem portion to the lower end of which is fixedgthe hanger or bracket .26' as indicatedrby a'horizontal rowo'f-screw :bolts I25. Asp-lash guard or skirt G is shown to be suspended from the casing member BI as indicated by suspensionstrips 'Gi A longitudinal strip like horizontal separation member G2 extends :withinthe skirt'G from end. to end thereof.

The I operation of the lubricating svstemiis dependent upon the functioning of the classifier,

15 by the oscillations of the finger 88 enga ing Dump plunger 88.

The operating cycle of the pump is as follows: As the finger 38 moves in the direction of arrow W, it moves the plunger 89 inwardly with respect. to the reservoir 36, so that the piston 89 by its outer full face F1 draws spent oil into the cylinder 65 from the collecting chamber 46 at the foot end of the machine, namely through pipe 41, flexible tube 5|, and pipe 49 into the valve head H, there through-passage l5 and check valves 18 and I1 into the pump cylinder, while check valve 82 remains closed due to the suction at this time in passage 15. Referring to Figure 14, this means that the oil enters the valve head 1| through pipe 49, passes through the valve head along the dot-and-dash line arrows A2 and through opening 19 out from the valve head and. into the outer end of pump cylinder 85. At the end of this plunger stroke, as the actuating finger 38 swings in the opposite direction as indicated by arrows W2, the oil is thereby expelled from the cylinder by plunger face F1 through passage 88 in the valve head, leaving the valve head by way of opening 85, then byway of passage 81 through the wall of the reservoir 38 entering the spent-oil receiving chamber 60, the pump pressure from piston face F1 meanwhile keeping the check valves 18 and 1! closed.

The oil thus being pumped into chamber 68 is thus forced through filter medium 59 into chamber 8| where the very same reciprocation of the pump plunger 69 pumps the oil through the upstanding pipe 64 into the discharge and distributing chambers 68. That is to say, when the plunger is moved inwardly with respect to the reservoir, the annular piston face F2 acts to draw filtered oil through check valve 88 from chamber 6| into the annular cylinder space 89 surrounding the plunger stem, while the suction caused by face F2 keeps the check valve 90 closed. The subsequent movement of the plunger in the direction outwardly from the reservoir displaces the oil from the inner end of the cylinder through check valve 80 into chambers 63, the expelling pressure meanwhile keeping the check valve 88 closed. From chambers 63 the oil gravitates through the pipes 40 and 4| to the upper pair of track members 28 and 28 entering the same through their inlet trunnions 39 and 39 to lubricate the two track elements 92* and 93 therein while carrying away dust particles which may have entered a track member from below through openings 0 and thus may have reached the track members or the interior of the track members, the oil in fact gravitating along the inclined tracks, to leave the'track members 38"- and 39 through their respective outlet trunnions 39 and 39 This once-spent oil continues through pipes 44 and 45 to enter the lower pair of track members 29 and 29 entering the same through their respective inlet trunnions 39 and 39 to lubricate the two track elements therein while again carrying away dust particles which might have reached the tracks or the interior of the track members, the thus twice-spent oil to leave the lower pair of track members through their outlet trunnions 39 and 39 whence it reaches the collecting chamber 46 by way of the pipes 44 and 45*. From the collecting chamber 48 the outer piston face F1 again draws the spent oil back into the reservoir 36 for filtration and rte-distribution. Y

The oscillation of the shaft I9 and thereby of the-collecting chamber 48 agitates the oil which is in transit through the hard-to-get-at collecting chamber 46; thus tending to prevent the formation of any appreciable amount of sediment or sludge in that chamber, and causing particles suspended in the spent oil to be pumped up into the stationary and accessible reservoir 86 to allow such particles to be deposited there in the chamber 60 whence they can be readily removed or flushed as sludge or sediment through an outlet or cleaning hole 5 closed by a removable plug H8".

The condition and amount of oil in circulation can be readily checked and observed by inspecting the oil in reservoir 38 after removal of the cover plate 51. Also, since the flow of oil passing through the valve head H can be observed because of the transparent nature of the material of which it is made, this valve head furnishes a convenient and important means to ascertain at all times and instantaneously whether oil is circulating in the system and the pump is operating normally.

I claim:

1. Incombination with a twin rake classifier having a tank providing an inclined deck, a pair of rake structures disposed side by side in said tank, each rake structure being adapted to perform a bodily cyclic movement comprising an upward solids-raking stroke and an elevated return stroke, an actuating mechanism for imparting said cylic movements to said rake structures comprising an inclined medial oscillatable shaft extending from the foot end to the head end of the tank, a pair of upper arm structures extending laterally in opposite directions from the shaft, a pair of lower arm structures'extending laterally in opposite directions from the shaft and spaced downwardly along the shaft a distance from said upper arm structures, each upper and each lower arm structure carrying an oscillatable track: member coextensive with said shaft and oscillatable about a longitudinal axis parallel to'that of the oscillatable shaft, an upper and a lower track member at each side of the inclined shaft serving to reciprocably support respective upper and lower end portions of a respective rake structure, said mechanism further comprising a drive head at the upper end of the deck for oscillating the inclined shaft as well as for longitudinally reciprocating the rake structures in a manner of coordination whereby said cyclic movements are imparted to said rake structures; an oil circulating lubricating system for continuously supplying oil to said tracks and returning spent oil therefrom for redistribution to said tracks, comprising an oil reservoir at the head of the tank, a double-acting plunger pump having a plungerholding pump cylinder associated with the reservoir at the head of the tank, plunger-actuating means effective between the upper end of the shaft and the pump to effect reciprocation of the plunger by and in time with the oscillations of the shaft, said plunger being effective at one side thereof to draw oil from the reservior and to deliver it to said track members to gravitate therethrough and as spent oil therefrom to a low point, a sump for the spent oil at said low point. said plunger being effective at the other side thereof to draw spent oil from said low point and to deliver it into said reservoir, and discharge conduit means for gravitationally passing oil from, the reservoir to said track members, and suction conduit means for oil to pass from said low point to, said pump.

2. The combination according to claim 1, in which said plunger actuating means comprise an actuating finger rigidly connected with the upper end of said shaft to oscillate therewith, said finger having direct actuating relationship with said Plunger.

3. The combination according to claim 1, in which said pump has its free plunger end extend into the reservoir, and in which said plunger actuating means comprise an axial extension member at the upper end of said shaft also extending into said reservoir, an actuating finger rigidly extending from said member within said reservoir and oscillatable with said shaft, said finger having direct actuating relationship with said plunger.

4. The combination according to claim 1, in which the pump cylinder is mounted in the wall of the reservoir in a manner whereby the free plunger end extends into the reservoir and the outwardly facing head end of the pump is fixedly associated with the outer face of the wall, and in which said plunger actuating means comprise an axial extension member at the upper end of said shaft extending into said reservoir, an actuating finger rigidly extending from said member within said reservoir and having direct actuating relationship with said plunger.

5. The combination according to claim 1, in which the reservoir has a filter member dividing the reservoir into a lower spent oil receiving chamber having an inlet port and an upper filtered oil chamber supplied with oil rising from the lower chamber through said filter member into the upper chamber, said pump cylinder being mounted in the wall of the reservoir in a manner to have the inwardly facing free plunger end extend into the filtered oil chamber and to have the outwardly facing head end of the pump cylinder fixedly and detachably associated with the outer face of the wall, said plunger actuating means comprising an axial extension member at the end of said shaft extending into said filtered oil chamber, and actuating finger rigidly extending from said extension member within said filtered oil chamber and having direct actuating relationship with said plunger, and a valved end member detachably closing the outer end of the pump cylinder, said closing member having a check valved pump discharge port registering with said lower chamber inlet port for delivering thereto oil drawn from said low point by said one side of the plunger.

CHARLES H. SCOTT.

No references cited.

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